(1) Field of the Invention
This invention relates to a substrate treating apparatus for performing various treatments, such as etching treatment, stripping treatment and cleaning treatment, of film-coated substrates such as semiconductor wafers or glass substrates for liquid crystal displays (hereinafter called simply substrates).
(2) Description of the Related Art
Conventionally, this type of substrate treating apparatus includes an inner tank for storing a treating solution, an outer tank for collecting the treating solution overflowing the inner tank, a circuit for circulating the treating solution from the outer tank to the inner tank, a pump mounted on the circuit, and a filter for removing particles and the like from the treating solution flowing through the circuit (see Japanese Unexamined Patent Publication No. 2001-358134 (FIG. 1), for example).
The apparatus having the above construction stores a treating solution such as hydrofluoric acid in the inner tank, and immerses substrates coated with photoresist film in the treating solution to etch portions of the substrates not masked by the photoresist film. After this treatment, a treating solution containing sulfuric acid and hydrogen peroxide solution is introduced into the inner tank, and the substrates coated with the photoresist film are immersed therein to strip off and remove the photoresist film itself.
The conventional apparatus noted above has the following drawback.
In the conventional apparatus, the filter is often clogged with the photoresist film stripped off, and must be changed frequently. As a result, an increased number of halts occur with the apparatus for filter changing operations, hence a problem of low working efficiency of the apparatus.